1. Field of the Invention
The present invention relates to an objective lens for a medical or industrial endoscope.
2. Description of Related Art
In an objective lens for an endoscope, attempts have been made to eliminate chromatic aberration and particularly, transverse chromatic aberration, which deteriorates an image quality.
For example, the assignee of the present application has proposed a lens arrangement to reduce the transverse chromatic aberration in Japanese Unexamined Patent Publication No. 63-293515. In this proposal, the improvement was directed at the requirements for the Abbe number of a glass material to be used, but there was no specific reference to a relative partial dispersion of the glass material.